Motor controller for draft inducer motor in a furnace and method of use

ABSTRACT

A motor controller for a draft inducer motor that operates an inducer blower in a furnace is provided. The motor controller includes a communication interface operable to receive a signal from a system controller. The signal represents a command to operate the draft inducer motor. The motor controller includes a processor operable to operate the draft inducer motor in accordance with a predefined motor speed profile during at least one of an ignition stage and a combustion stage of the furnace.

BACKGROUND

The field of the disclosure relates generally to airflow in furnaces,and more specifically to a motor controller for a draft inducer motor ina furnace.

New regulations limit emission of dangerous combustion gas by-products,such as NO_(x), in gas-burning appliance applications, for example,furnaces used in heating, ventilation, and air conditioning (HVAC)systems. To reduce emissions to comply with such regulations, somemanufacturers have implemented burner design changes to provide higherflow rates and pressure of combustion gasses, which are required duringa burning stage of the furnace to meet the new standards for efficiencyand low by-product emissions. The higher flow rate and pressure causesdraft inducers to have to run at much higher speeds. However, at thespeeds required for steady state combustion, successful and reliableignition of the burners is difficult due to increased turbulence at theburners. Further, the ignition process generates excessive amounts ofnoise that may cause discomfort to people nearby.

One known solution to achieve reliable ignition, while also meeting theincreased efficiency standards, is to use variable speed blowers.However, use of variable speed blowers requires advanced controllerscapable of generating and outputting pulse-width-modulation (PWM)signals to control the variable speed motors. The need for such advancedcontrollers poses an increased cost to manufacturers to switch fromstandard low cost control systems to significantly more expensiveadvanced control systems.

Another known solution includes using a two-speed control method, wherea system controller commands the draft inducer to operate at a low speedsetting for ignition and a high speed setting for steady-statecombustion speed. However, these two-speed control methods require theaddition of external relays for each speed setting to the system controlboard. Adding external relays increases cost and spacing requirementsassociated with the system control board. Additionally, the two-speedmethods are limited to the two speed settings and offer littleflexibility in adjusting motor speed points.

BRIEF DESCRIPTION

In one aspect, a motor controller for a draft inducer motor thatoperates an inducer blower in a furnace is provided. The motorcontroller includes a communication interface operable to receive asignal from a system controller. The signal represents a command tooperate the draft inducer motor. The motor controller includes aprocessor operable to operate the draft inducer motor in accordance witha predefined motor speed profile during at least one of an ignitionstage and a combustion stage of the furnace.

In another aspect, a method of controlling a draft inducer motor thatoperates an inducer blower in a furnace is provided. The method includesreceiving, by a communication interface of a motor controller, a signalfrom a system controller, the signal representing a command to operatethe draft inducer motor. The method also includes operating, by aprocessor of the motor controller, the draft inducer motor in accordancewith a predefined motor speed profile during at least one of an ignitionstage and a combustion stage of the furnace.

In yet another aspect, a furnace is provided that includes an inducerblower, a draft inducer motor coupled to and operable to drive theinducer blower, and a motor controller. The motor controller includes acommunication interface operable to receive a signal representing acommand to operate the draft inducer motor, and a processor operable tooperate the draft inducer motor in accordance with a predefined motorspeed profile during at least one of an ignition stage and a combustionstage of the furnace.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an exemplary furnace;

FIG. 2 is a detailed block diagram of a motor controller for use in thefurnace shown in FIG. 1; and

FIG. 3 is a flow diagram of an exemplary method of controlling aninducer blower in the furnace shown in FIGS. 1 and 2.

FIG. 4 is a graph showing an exemplary motor speed profile that may beimplemented by the motor controller shown in FIGS. 1 and 2.

DETAILED DESCRIPTION

As used herein, an element or step recited in the singular and precededwith the word “a” or “an” should be understood as not excluding pluralelements or steps, unless such exclusion is explicitly recited.Furthermore, references to “example implementation” or “oneimplementation” of the present disclosure are not intended to beinterpreted as excluding the existence of additional implementationsthat also incorporate the recited features.

Gas furnaces burn a mixture of air and a fuel to generate heat that iscarried by combustion gasses. The combustion gasses are typically drawnthrough a heat exchanger by a blower, and then vented out through anexhaust duct. To meet increasingly stringent efficiency and by-productemissions standards, manufacturers have implemented burner designchanges to provide higher flow rates and pressure of the combustiongasses. However, these burner design changes have also added significantairflow restriction in the burners, resulting in the draft inducersrunning at much higher speeds. The higher speeds induce higher rates ofairflow. If the airflow is too great, ignition of the combustion gassesbecomes difficult and unreliable. Motor controllers described hereininterface with standard, low-cost system controllers to receive anoperation command signal, and regulate motor speed for the blower duringan ignition phase to generate low airflow to improve ignitionreliability, and regulate motor speed for the blower after the ignitionphase to generate higher airflow and to provide a high-quality burn withlow by-product emissions.

FIG. 1 is a schematic view of an exemplary furnace 100. The primarycomponents of furnace 100 include a burner compartment 102 and a heatexchanger 104. A gas valve 168 that may be electrically or pneumaticallyregulated, provides fuel such as natural gas or propane, from a source(not illustrated) to burner compartment 102 via a gas line 106. Burnercompartment 102 burns the fuel provided by gas valve 108, and providesheated combustion gasses to heat exchanger 104. The heated combustiongasses pass through heat exchanger 104, and are ultimately exhausted tothe exterior of the building or home in which furnace 100 is installed.

In the illustrative furnace, a circulating blower 110 accepts return airfrom return ductwork 112 of a building or home as indicated by arrow 114and blows the return air through heat exchanger 104, thereby heating thereturn air. The heated air exits heat exchanger 104 and is provided backinto the building or home via conditioned air ductwork 116, traveling ina direction indicated by arrow 118.

Furnace 100 includes a system controller 120 operable to control variouscomponents of furnace 100, including the ignition of fuel by an ignitionelement (not shown), the operation of gas valve 108, and the speed andoperation times of circulating blower 110. In addition, systemcontroller 120 may further be configured to monitor and/or controlvarious other aspects of the system including any damper and/or divertervalves connected to the supply air ducts, any sensors used for detectingtemperature and/or airflow, any sensors used for detecting filtercapacity, and any shut-off valves used for shutting off the supply ofgas to gas valve 108. In the control of other gas-fired appliances suchas water heaters, for example, system controller 120 may also be taskedto perform other functions such as water level and/or temperaturedetection, as desired. In some embodiments, system controller 120 isfurther operable to communicate with one or more thermostats or the like(not shown) for receiving calls for heat, sometimes from variouslocations within the building or structure. It should be understood,however, that system controller 120 may be configured to provideconnectivity to a wide variety of platforms and/or standards, asdesired. System controller 120 may provide commands to circulatingblower 110 via an electrical line 122. In some instances, systemcontroller 120 may electrically control gas valve 108 by transmittingcommand signals via an optional electrical line 124.

Furnace 100 includes an inducer blower 126 positioned downstream of heatexchanger 104 that draws combustion gases through heat exchanger 104.Inducer blower 126 may be considered as pulling combustion air intoburner compartment 102 through an inlet duct 128 to provide an oxygensource for supporting combustion within burner compartment 102. Thecombustion air moves in a direction indicated by arrow 130. Combustiongasses, which may include NO_(x) gasses, pass through heat exchanger104, and ultimately are exhausted through an exhaust duct 132 in adirection indicated by arrow 134. Although inducer blower 126 is shownas being positioned proximate exhaust duct 132, it is contemplated, inalternative embodiments, that inducer blower 126 may be positionedanywhere between inlet duct 128 and exhaust duct 132. For example,inducer blower 126 may be located upstream of burner compartment 102 topush air through burner compartment 102, rather than downstream to pullair through burner compartment 102, as is shown in FIG. 1.

Furnace 100 includes a draft inducer motor 136 configured to driveinducer blower 126 to generate the airflow 130 into inlet duct 128. Inat least some embodiments, draft inducer motor 136 is a variable speedmotor configured to convert electrical power into mechanical power. Inalternative embodiments, draft inducer motor 136 is a permanent magnetmotor. In one example, draft inducer motor 136 is coupled to a wheel(not shown) of inducer blower 126 and is configured to rotate the wheel.In the exemplary embodiment, draft inducer motor 136 is configured tooperate at a plurality of speed output levels (i.e., speed-controlled)to increase or decrease a corresponding motor speed. Increasing ordecreasing the motor speed of draft inducer motor 136 causes draftinducer motor 136 to drive inducer blower 126 to generate correspondingairflow volumes. The airflow volume generated by inducer blower 126 isat least partially a function of the motor speed of draft inducer motor136.

A motor controller 138 is communicatively coupled to draft inducer motor136 to operate draft inducer motor 136. Motor controller 138 controlsdraft inducer motor 136 by transmitting a control signal representing avariable motor speed. The control signal may be implemented, forexample, and without limitation, as a square wave. In certainembodiments, the control signal may undergo pulse width modulation toaffect a change in duty cycle that represents a motor speed set-point.More specifically, motor controller 138 supplies current having acertain amplitude and frequency to the stator windings of draft inducermotor 136 to operate draft inducer motor 136. By adjusting the currentand frequency, motor controller 138 controls the speed of draft inducermotor 136.

Motor controller 138 is communicatively coupled to system controller 120and is configured to receive command signals from system controller 120via an electrical line 140 instructing draft inducer motor 136 whetheror not to operate. For example, possible implementations of electricalline 140 may include, but are not limited to, discrete, serial,parallel, analog, and/or digital communications. More specifically,system controller 120 includes an internal relay 142 that, when closed,provides a signal to motor controller 138. The signal may be any type ofsignal including, but not limited to, a logic level signal, atransistor-transistor logic (TTL) signal, and/or an AC/DC signal. If thesignal is an AC/DC signal, it may be either a low-voltage signal (i.e.,less than 20 VDC) or a line (high) voltage signal (i.e., at least 60VAC). Alternatively, there may be no command signal, and a user couldswitch power to draft inducer motor 136 directly. When motor controller138 receives the signal from system controller 120, motor controller 138operates draft inducer motor 136 in accordance with a predefined speedprofile that facilitates gas ignition, as described in more detailbelow. When system controller 120 opens relay 142, the signal is nolonger received by motor controller 138, and motor controller 138 stopsoperation of draft inducer motor 136.

FIG. 2 is a detailed block diagram of motor controller 138 (shown inFIG. 1) used in furnace 100 (shown in FIG. 1). Motor controller 138includes a processor 200, and a memory 202 communicatively coupled toprocessor 200. Processor 200 is configured to execute instructionsstored within memory 202 to cause motor controller 138 to function asdescribed herein. For example, memory 202 is a non-transitory memorythat stores computer-executable instructions and data for operatingmotor controller 138. In certain embodiments, motor controller 138 isconfigured to store stores a speed profile in memory 202 to be executedby processor 200 to operate draft inducer motor 136. In someembodiments, motor controller 138 may include a plurality of processors200 and/or memories 202. In other embodiments, memory 202 may beintegrated with processor 200. In one example, memory 202 includes aplurality of data storage devices to store instructions and data asdescribed herein.

Motor controller 138 includes a drive circuit 204. Drive circuit 204supplies electric power to the stator windings of draft inducer motor136 based on control signals received from processor 200. Drive circuit204 may include, for example, various power electronics for conditioningline frequency alternating current (AC) power to be supplied to thestator windings of draft inducer motor 136 with a desired current, i.e.,phase and amplitude, and frequency. Such power electronics may include,for example, and without limitation, one or more rectifier stages, powerfactor correction (PFC) circuits, filters, transient protectioncircuits, EMF protection circuits, inverters, or power semiconductors.

Motor controller 138 includes a communication interface 206.Communication interface 206 may include one or more wired or wirelessinterface, such as, for example, universal serial bus (USB), RS232 orother serial bus, CAN bus, Ethernet, near field communication (NFC),WiFi, Bluetooth, or any other suitable interface for establishing one ormore communication channels between motor controller 138 and one or moreexternal devices, such as system controller 120, an external programmingdevice, and/or any other device that enables motor controller 138 tofunction as described herein.

In the exemplary embodiment, communication interface 206 includes aninput terminal 208 configured to be electrically coupled to systemcontroller 120, and more specifically, to relay 142, using electricalwire 140 such that wired signals may be transmitted therebetween. Forexample, wired signals may include, but are not limited to, discrete,serial, parallel, analog, and/or digital communication, and/or any otherknown types of wired signals. Because motor controller 138 performs allof the speed determination and controlling of draft inducer motor 136and the only input provided by system controller 120 is a command tostart/stop draft inducer motor 136, input terminal 208 is a simplifiedthe interface between motor controller 138 and system controller 120, ascompared to known interfaces. That is, input terminal 208 provides aconnection for motor controller 138 to relay 142, a standard componenton most furnace system control boards. Thus, in some embodiments, draftinducer motor 136 with motor controller 138 may be used as a drop-inreplacement for standard induction motors without having to change orupgrade system controller 120. More specifically, system controller 120does not provide speed control signals to motor controller 138. Morespecifically, system controller 120 provides neither discrete signalsusing multiple relays, each associated with a respective speed, nor PWMsignals generated by system controller 120. Conversely, using multiplerelays increases costs and spacing requirements on system controller120, and provide inflexible control of motor speed. Using PWM signalsrequires advanced system controls, which are significantly moreexpensive than standard controls and require the use of a variable speedmotor, adding even more costs.

In the exemplary embodiment, communication interface 206 includes awireless module 210 configured to receive and/or transmit wirelesssignals from/to external devices. For example, wireless signals mayinclude, but are not limited to, Bluetooth, Bluetooth low energy, nearfield communications (NFC), infrared, and/or any other known types ofwireless signals. In the exemplary embodiment, the motor speed profileis wirelessly programmed into a configurable portion of memory 202either while on the assembly line during manufacturing or while packagedfor shipment. The parameters of the motor speed profile are provided toa programming computer device that wirelessly transmits the motor speedprofile to motor controller 138. The signal including the motor speedprofile is received by wireless module 210 and is stored on memory 202.Once draft inducer motor 136 and motor controller 138 are installed infurnace 100 and motor controller 138 receives a command signal fromsystem controller 120 to operate, processor 200 retrieves the motorspeed profile from memory 202 and applies it to control operation ofdraft inducer motor 136.

FIG. 3 is a flow diagram of an exemplary method 300 of controllinginducer blower 126 in furnace 100 (shown in FIGS. 1 and 2). FIG. 4 is agraph showing an exemplary motor speed profile 400 that may beimplemented by motor controller 138 (shown in FIGS. 1 and 2). At areceiving step 302, motor controller 138 receives a signal from systemcontroller 120 via electrical line 140. The signal represents a commandfrom system controller 120 to operate draft inducer motor 136. Uponreceiving the signal, at an operating step 304, motor controller 138operates draft inducer motor 136 in accordance with a stored motor speedprofile during at least one of an ignition stage and a combustion stageof the furnace. The stored motor speed profile facilitates automaticramping speed control and timing of draft inducer motor 136 to achievemore reliable and less noisy gas ignition.

In some embodiments, operating step 304 includes motor controller 138ramping a speed of draft inducer motor 136 up to a first (or ignition)motor speed 402 over a first time period 404 to cause inducer blower 126to generate airflow 130 through inlet duct 128. Motor controller 138then maintains the speed of draft inducer motor 136 at the first motorspeed 402 for a second time period 406 during the ignition stage of thefurnace. During the second time period 406, while draft inducer motor136 is operating inducer blower 126 to generate airflow 130, systemcontroller 120 controls gas flow into burner compartment 102. Ignitionof the burners should occur within burner compartment 102 during thesecond time period. For example, the second time period may be 90seconds or any other desired time period. The value of the first motorspeed may vary depending on the size of the furnace in which draftinducer motor 136 is installed, as the speed needed to achieve areliable ignition varies depending on furnace size. The first motorspeed is significantly lower than a steady-state combustion speed atwhich draft inducer motor 136 is designed to operate during normaloperation of furnace 100. Accordingly, the first speed may be, forexample, within a range of 1,000-3,000 RPM, depending on furnace size.Alternatively, any other first speed may be used that enables furnace100 to function as described herein.

In optional embodiments, upon completion of the second time period 406,motor controller 138 ramps a speed of draft inducer motor 136 up to asecond (or intermediate) motor speed 408 over a third time period 410.After the third time period 410, motor controller 138 maintains thespeed of draft inducer motor 136 at the second motor speed 408 to enableburner stabilization, if desired. In such embodiments, the second motorspeed 408 may be an intermediate speed between the light-off speed andthe steady-state combustion speed. For example, the second motor speed408 may be within a range of 2,500-4,500 RPM. The intermediate speedenables the burners in furnace 100 to stabilize for periods longer thanwould be feasible using ramp rates. This may be desired because as theburners are ramped up, relatively hotter and cooler spots are developed,and the stabilization period allows the temperature differences to bereduced before ramping up to steady-state operation. Motor controller138 maintains the speed of draft inducer motor 136 at the second motorspeed 408 for a fourth time period 412.

Upon completion of the fourth time period 412, motor controller 138ramps a speed of draft inducer motor 136 up to a third (steady-statecombustion) motor speed 414 over a fifth time period 416. After thefifth time period 416, motor controller 138 maintains the speed of draftinducer motor 136 at the third motor speed 414 during the combustionstage of the furnace. In such embodiments, the third motor speed 414 isthe final steady-state combustion speed that corresponds to an airflowat which furnace 100 is designed to operate. For example, the thirdmotor speed 414 may be within a range of 4,000-6,000 RPM. Motorcontroller 138 powers off draft inducer motor 136 when the signal is nolonger received from system controller 120.

Motor controllers described herein control a draft inducer motor tooperate an inducer blower to generate low airflow to improve ignitionreliability during an ignition phase and to achieve high-efficiencycombustion and heat exchange with low by-product emissions after theignition phase. Embodiments of the motor controller described hereinprovide a simple interface with standard, low-cost system controllers toreceive an operation command signal. Upon receiving the operationcommand signal, motor controllers described herein operate the draftinducer motor in accordance with a predefined motor speed profile tocontrol the airflow to a reasonable level depending on the phase ofoperation of the furnace.

The methods and systems described herein may be implemented usingcomputer programming or engineering techniques including computersoftware, firmware, hardware or any combination or subset thereof,wherein the technical effect may include at least one of: (a) operatingan inducer blower for a furnace at a variable speed; (b) controllingairflow through a furnace based on a phase of operation of the furnace;(c) improving ignition reliability of the burners by controlling thedraft inducer motor to generate a low airflow during an ignition phase;(d) improving efficiency of combustion and heat transfer in the furnace,while achieving low by-product emissions; and (e) simplifying theinterface to be operable with standard, low-cost system controllers.

Some embodiments involve the use of one or more electronic or computingdevices. Such devices typically include a processor, processing device,or controller, such as a general purpose central processing unit (CPU),a graphics processing unit (GPU), a microcontroller, a reducedinstruction set computer (RISC) processor, an application specificintegrated circuit (ASIC), a programmable logic circuit (PLC), a fieldprogrammable gate array (FPGA), a digital signal processing (DSP)device, and/or any other circuit or processing device capable ofexecuting the functions described herein. The methods described hereinmay be encoded as executable instructions embodied in a computerreadable medium, including, without limitation, a storage device and/ora memory device. Such instructions, when executed by a processingdevice, cause the processing device to perform at least a portion of themethods described herein. The above examples are exemplary only, andthus are not intended to limit in any way the definition and/or meaningof the terms processor, processing device, and controller.

In the embodiments described herein, memory may include, but is notlimited to, a computer-readable medium, such as a random access memory(RAM), and a computer-readable non-volatile medium, such as flashmemory. Alternatively, a floppy disk, a compact disc-read only memory(CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc(DVD) may also be used. Also, in the embodiments described herein,additional input channels may be, but are not limited to, computerperipherals associated with an operator interface such as a mouse and akeyboard. Alternatively, other computer peripherals may also be usedthat may include, for example, but not be limited to, a scanner.Furthermore, in the exemplary embodiment, additional output channels mayinclude, but not be limited to, an operator interface monitor.

As used herein, the terms “software” and “firmware” are interchangeable,and include any computer program stored in memory for execution by aprocessor, including RAM memory, ROM memory, EPROM memory, EEPROMmemory, and non-volatile RAM (NVRAM) memory. The above memory types areexamples only, and are thus not limiting as to the types of memoryusable for storage of a computer program.

The systems and methods described herein are not limited to the specificembodiments described herein, but rather, components of the systemsand/or steps of the methods may be utilized independently and separatelyfrom other components and/or steps described herein.

This written description uses examples to provide details on thedisclosure, including the best mode, and also to enable any personskilled in the art to practice the disclosure, including making andusing any devices or systems and performing any incorporated methods.The patentable scope of the disclosure is defined by the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal language of the claims.

What is claimed is:
 1. A motor controller for a draft inducer motor thatoperates an inducer blower in a furnace, said motor controllercomprising: a memory configured to store a predefined motor speedprofile, wherein the predefined motor speed profile defines a firstramping time period comprising a first stored duration, an ignitionstage time period comprising a second stored duration, a first motorspeed for the ignition stage time period, a second ramping time periodcomprising a third stored duration, and a second motor speed for acombustion stage, and wherein a value of the first motor speed isdetermined based on a size of the furnace; a communication interfaceoperable to receive a signal from a system controller, the signalrepresenting a command to operate the draft inducer motor; and aprocessor operable to operate the draft inducer motor in accordance withthe predefined motor speed profile during at least one of 1) the firstramping time period and the ignition stage time period, and 2) thesecond ramping time period and the combustion stage of the furnace. 2.The motor controller of claim 1, wherein said communication interfacecomprises an input terminal configured to be coupled to a relay of thesystem controller, said input terminal operable to receive the signalfrom the system controller.
 3. The motor controller of claim 2, whereinsaid input terminal is operable to receive at least one of a discretesignal, a serial signal, a parallel signal, an analog signal, and adigital communication signal.
 4. The motor controller of claim 1,wherein said processor, in operating the draft inducer motor inaccordance with the predefined motor speed profile, is further operableto: ramp a speed of the draft inducer motor up to the first motor speedover a first ramping time period to cause the inducer blower to generateairflow through an inlet duct of the furnace; maintain the speed of thedraft inducer motor at the first motor speed for a second time period,the second time period representing the ignition stage time period,during the ignition stage of the furnace; ramp a speed of the draftinducer motor up to the second motor speed over a third time period, thethird time period representing the second ramping time period, uponcompletion of the second time period; and maintain the speed of thedraft inducer motor at the second motor speed upon completion of thethird time period during the combustion stage of the furnace.
 5. Themotor controller of claim 4, wherein the first motor speed is lower thana steady-state combustion speed, wherein the first motor speed is aspeed at which the draft inducer motor operates to facilitate gasignition in a burner compartment of the furnace.
 6. A motor controllerfor a draft inducer motor that operates an inducer blower in a furnace,said motor controller comprising: a memory configured to store apredefined motor speed profile, wherein the predefined motor speedprofile defines a first ramping time period, an ignition stage timeperiod, a first motor speed for the ignition stage time period, and asecond ramping time period, and a second motor speed for a combustionstage, and wherein a value of the first motor speed is determined basedon a size of the furnace; a communication interface operable to receivea signal from a system controller, the signal representing a command tooperate the draft inducer motor; and a processor operable to operate thedraft inducer motor in accordance with the predefined motor speedprofile during at least one of 1) the first ramping time period and theignition stage time period, and 2) the second ramping time period andthe combustion stage of the furnace.
 7. The motor controller of claim 6,wherein the value of the first motor speed is within a range of1,000-3,000 revolutions per minute (RPM).
 8. The motor controller ofclaim 4, wherein the second motor speed is a steady-state combustionspeed that corresponds to an airflow at which the furnace is designed tooperate.
 9. The motor controller of claim 8, wherein the value of thesecond motor speed is within a range of 4,000-6,000 RPM.
 10. The motorcontroller of claim 1, wherein said processor is further operable topower off the draft inducer motor when the signal is no longer receivedfrom the system controller.
 11. The motor controller of claim 1, whereinsaid communication interface comprises a wireless module configured toreceive wireless programming signals from an external programmingcomputer device.
 12. The motor controller of claim 11, wherein thewireless programming signals include the predefined motor speed profile.13. The motor controller of claim 12, wherein the predefined motor speedprofile is programmed into the memory while the draft inducer motor ison an assembly line during manufacture or while the draft inducer motoris packaged for shipment.
 14. The motor controller of claim 11, whereinthe wireless programming signals are at least one of Bluetooth signals,Bluetooth low energy signals, near field communications (NFC) signals,and infrared signals.
 15. A method of controlling a draft inducer motorthat operates an inducer blower in a furnace, said method comprising:storing, in a memory, a predefined motor speed profile, wherein thepredefined motor speed profile defines a first ramping time periodcomprising a first stored duration, an ignition stage time periodcomprising a second stored duration, a first motor speed for theignition stage time period, a second ramping time period comprising athird stored duration, and a second motor speed for a combustion stage,and wherein a value of the first motor speed is determined based on asize of the furnace; receiving, by a communication interface of a motorcontroller a signal from a system controller, the signal representing acommand to operate the draft inducer motor; and operating, by aprocessor of the motor controller, the draft inducer motor in accordancewith the predefined motor speed profile during at least one of 1) thefirst ramping time period and the ignition stage time period, and 2) thesecond ramping time period and the combustion stage of the furnace. 16.The method of claim 15, further comprising: coupling an input terminalof the communication interface to a relay of the system controller; andreceiving, by the input terminal, the signal from the system controller,wherein the signal includes at least one of a discrete signal, a serialsignal, a parallel signal, an analog signal, and a digital communicationsignal.
 17. The method of claim 15, wherein operating the draft inducermotor in accordance with the predefined motor speed profile, furthercomprises: ramping, by the processor, a speed of the draft inducer motorup to the first motor speed over a first ramping time period to causethe inducer blower to generate airflow through an inlet duct of thefurnace; maintaining, by the processor, the speed of the draft inducermotor at the first motor speed for a second time period, the second timeperiod representing the ignition stage time period, during the ignitionstage of the furnace; ramping, by the processor, a speed of the draftinducer motor up to the second motor speed over a third time period, thethird time period representing the second ramping time period, uponcompletion of the second time period; and maintaining, by the processor,the speed of the draft inducer motor at the second motor speed uponcompletion of the third time period during the combustion stage of thefurnace.
 18. A furnace comprising: an inducer blower; a draft inducermotor coupled to said inducer blower and operable to drive said inducerblower to generate an airflow; and a motor controller comprising: amemory configured to store a predefined motor speed profile, wherein thepredefined motor speed profile defines a first ramping time periodcomprising a first stored duration, an ignition stage time periodcomprising a second stored duration, a first motor speed for theignition stage time period, a second ramping time period comprising athird stored duration, and a second motor speed for a combustion stage,and wherein a value of the first motor speed is determined based on asize of the furnace; a communication interface operable to receive asignal representing a command to operate the draft inducer motor; and aprocessor operable to operate said draft inducer motor in accordancewith the predefined motor speed profile during at least one of 1) thefirst ramping time period and the ignition stage time period, and 2) thesecond ramping time period and the combustion stage of the furnace. 19.The furnace of claim 18, further comprising a system controllerincluding a relay, wherein said system controller closes said relay totransmit the signal to said motor controller.
 20. The furnace of claim19, wherein said communication interface comprises an input terminalconfigured to be coupled to said relay of said system controller, saidinput terminal operable to receive the signal from said systemcontroller.